docs: def _parse_content_type(self, value):
          """
          Split the content-type header into two parts:
          1) Actual main/sub encoding type
          2) charset
  
          :param value: Complete MIME content-type string
          """
          content_type, params = parse_header(value)
          if 'charset' in params:
              charset = params['charset']
          else:
              charset = None
          return content_type, charset